This piece originally appeared on Travel + Leisure.
Caves are one of those natural wonders that often remain one of the most intriguing and mysterious despite being huge tourist destinations. While a number of them have been discovered, there are still countless more that haven’t been explored. But, Vietnam is putting two more on the map by allowing—for the first time ever—expedition company Oxalis to lead tours of the Hang Va and Hang Nuoc Nut caves.
Not only do visitors get to explore the previously secluded cavern, but the trek will take a full two days to complete. You’ll walk through the jungle, mountains, and river to reach the caves and spend one night at a camp. “Some explorers commented that the stalactites and stalagmites in Va Cave are even more beautiful and extraordinary than Son Doong Cave,” Oxalis says.
This new trek comes after authorities allowed part of the famous Phong Nha – Ke Bang cavern system to be opened 16 years after they were discovered by locals, according to the Vietnamese government website. Act quick if you want to see this for yourself: the tour only runs three to four times per week and the maximum capacity is eight people per tour.
Related: The World's Coolest Caves